Tommy Cookers wrote:Can I again point out that I was complaining about the FIA and some others, not about the turbo, in part my complaint was about misrepresentation of how the turbo works.
To those who understand the technology there was never a misrepresentation. The FiA objective is to save 35% of the fuel use of the V8 engines by introducing technologies like turbocharging, hybrid turbocompounding, direct injection, spray guided combustion and exhaust gas recirculation.
In WW2 turbos were designed to run with upstream exhaust temperatures of 1725 F, presumably modern ones have a higher temperature capability.
The WWII aero engines were predominantly supercharged. Later they used exhaust turbines for turbocompounding 12% of the engine power from the exhaust gas stream. The mechanical compressor and the exhaust turbine were not connected.
To me this still suggests that turbos run on exhaust gases at higher energy conditions than the unsupercharged car engine generates..
The only difference is not in temperature but in back pressure from the turbine. A charged engine can deal better with the back pressure.
..whatever gases they run on, it's not the energy 'wasted' out of my Hyundai's tailpipe.
And at this point you are wrong. The turbine extracts energy from the exhaust gas that would otherwise be released to atmosphere unused.
Turbos only got into cars (via the competition route with rules much kinder than F1 rules), after 40 years of use in aircraft and diesels, so I'm thinking there was no compelling merit (for cars) then.
Turbochargers first massive use in automotive occurred in small European turbo diesel road cars. Atm about half the cars newly sold in the EU have turbo diesel engines. The USA did not follow that technology because these cars need diesel without sulfur. The EU refineries have supplied this type of fuel for a long time. In the USA it was practically unavailable. The diesel turbocharger runs on lower temperatures than the petrol version. It took the industry longer to offer modern turbochargers with variable geometries at higher temperature. The sulfur and the temp problem conspired to prevent the massive use of turbochargers in the USA in the past.
They became commercially attractive for homologation of competition winning 'production' cars and as a cheap route to profitable premium cars (cheaper/quicker route to power than building the necessarily bigger/different non-turbo engines). Years earlier fuel injection came in for the same reasons (Merc,Peugeot,Triumph)
I believe you are once again unaware of the market mechanisms. Downsized turbocharged engines with the same power output as NA engines are lighter, smaller and less thirsty. This is why they are increasingly used now.
Regarding tailpipe emission temperatures of turbo and other engines, do these show up in Rolling Road tests, does anyone have results in this area ?
If you start at 1000°C at the exhaust valve and end up with 20°C ambient temperature it matters a great deal if you recover between 200-400°C with a turbine or let it all cool down in muffler pots and pipes. It isn't relevant how hot your exhaust temp is from the tail pipe but how the temps came down to the that point.
Regarding the fuel injection developments associated with the 2014 rules, prssumably they are ,in principle, also valuable to designers of naturally aspirated engines ?
Yes they are.
They seem able to allow road car engines having the good characteristics of both diesel and petrol engines, I was assuming many would be n/a
The market will sort this out. The trend is clearly towards turbo engines everywhere because turbo engines generally have higher efficiency and fit into smaller spaces.
The traditional way of having good efficiency in real world use is to choose the engine size that we need, not twice that size. This applies with any type of engine.
The traditional way would be a specification that defines the power, the mileage, the weight and size of the engine and then the engineers design the engine to fit that brief. As I said above the most competitive engines will be turbo diesel and turbo petrol. Perhaps in the future also turbo compounded hybrids.
I wonder what FIAT says to the FIA, they have a conflict of interests I think.
Fiat and Ferrari are happy with the new turbo engines except they wanted a high cylinder count for marketing reason. They eventually got the L4 exchanged to the V6 and now they seem to be reasonably happy. Their view is to get rid of the frozen V8s and gain competitive advantages from the new engines.
